Electronic device and computer-readable recording medium

Abstract

An electronic device includes: a memory; a first infrared-ray emitter that emits a first infrared ray; a second infrared-ray emitter that emits a second infrared ray whose wavelength is partially overlapped with a wavelength of the first infrared ray; and a processor that is connected to the memory, the first infrared-ray emitter, and the second infrared-ray emitter. The processor is configured to determine whether an object is located in proximity to a device concerned during a proximity determination period based on a reflected light of the first infrared ray emitted, generate a capture image based on a reflected light of the second infrared ray emitted, conduct biometric authentication during an authentication period by using the capture image generated, and during the proximity determination period, stop emission of the second infrared ray or decrease an emission intensity of the second infrared ray from a reference level.

What is claimed is: 
     
         1 . An electronic device comprising:
 a memory;   a first infrared-ray emitter that emits a first infrared ray;   a second infrared-ray emitter that emits a second infrared ray whose wavelength is partially overlapped with a wavelength of the first infrared ray; and   a processor that is connected to the memory, the first infrared-ray emitter, and the second infrared-ray emitter, wherein   the processor is configured to
 determine whether an object is located in proximity to a device concerned during a proximity determination period based on a reflected light of the first infrared ray emitted, 
 generate a capture image based on a reflected light of the second infrared ray emitted, 
 conduct biometric authentication during an authentication period by using the capture image generated, and 
 during the proximity determination period, stop emission of the second infrared ray or decreases an emission intensity of the second infrared ray from a reference level while the first infrared ray is emitted. 
   
     
     
         2 . The electronic device according to  claim 1 , wherein when the second infrared ray is not emitted, the processor is further configured to set an exposure time of an image censor to a reference value and, when the second infrared ray is emitted, adjust the exposure time of the image censor in accordance with a brightness of the capture image generated. 
     
     
         3 . The electronic device according to  claim 2 , wherein in a case where the proximity determination period is included in the authentication period, the processor is further configured to use, as the reference value, the exposure time that is adjusted in the authentication period before the proximity determination period is started. 
     
     
         4 . The electronic device according to  claim 1 , wherein when it is determined that an object is located in proximity to a device concerned in the proximity determination period before the authentication period is started, the processor is further configured not to start the authentication period and, when it is determined that an object is not located in proximity to the device concerned in the proximity determination period before the authentication period is started, the processor is further configured to start the authentication period. 
     
     
         5 . A non-transitory computer-readable recording medium storing a biometric authentication program that causes a computer to execute a process comprising:
 emitting a first infrared ray;   emitting a second infrared ray whose wavelength is partially overlapped with a wavelength of the first infrared ray;   determining whether an object is located in proximity during a proximity determination period based on a reflected light of the first infrared ray emitted;   generating a capture image based on a reflected light of the second infrared ray emitted;   conducting biometric authentication during an authentication period by using the capture image generated; and   during the proximity determination period, stopping emission of the second infrared ray or decreasing an emission intensity of the second infrared ray from a reference level while the first infrared ray is emitted.